QAbstractScrollArea - add SizeAdjustPolicy and viewportSizeHint

This patch adds SizeAdjustPolicy to QAbstractScrollArea.
If it is set to AdjustToContents it will make use of the new
protected viewportSizeHint() (BC since it was reserved in Qt5).
This function returns a suggested size based on contents.

Change-Id: I5d8aa517e88b8b21c5712e62b4d574c3aad99d3b
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

8 files changed, 96 insertions, 2 deletions

diff --git a/src/widgets/itemviews/qabstractitemview.cpp b/src/widgets/itemviews/qabstractitemview.cpp
index 70c8f44a73..b79525b9df 100644
--- a/src/widgets/itemviews/qabstractitemview.cpp
+++ b/src/widgets/itemviews/qabstractitemview.cpp
@@ -1108,6 +1108,7 @@ void QAbstractItemView::reset()
         QAccessible::updateAccessibility(&accessibleEvent);
     }
 #endif
+    d->updateGeometry();
 }
 
 /*!
@@ -1124,6 +1125,7 @@ void QAbstractItemView::setRootIndex(const QModelIndex &index)
     }
     d->root = index;
     d->doDelayedItemsLayout();
+    d->updateGeometry();
 }
 
 /*!
@@ -2668,8 +2670,10 @@ void QAbstractItemView::updateEditorGeometries()
 */
 void QAbstractItemView::updateGeometries()
 {
+    Q_D(QAbstractItemView);
     updateEditorGeometries();
-    d_func()->fetchMoreTimer.start(0, this); //fetch more later
+    d->fetchMoreTimer.start(0, this); //fetch more later
+    d->updateGeometry();
 }
 
 /*!
@@ -3231,6 +3235,7 @@ void QAbstractItemView::dataChanged(const QModelIndex &topLeft, const QModelInde
         QAccessible::updateAccessibility(&accessibleEvent);
     }
 #endif
+    d->updateGeometry();
 }
 
 /*!
@@ -3332,6 +3337,7 @@ void QAbstractItemViewPrivate::_q_rowsRemoved(const QModelIndex &index, int star
         QAccessible::updateAccessibility(&accessibleEvent);
     }
 #endif
+    updateGeometry();
 }
 
 /*!
@@ -3412,6 +3418,7 @@ void QAbstractItemViewPrivate::_q_columnsRemoved(const QModelIndex &index, int s
         QAccessible::updateAccessibility(&accessibleEvent);
     }
 #endif
+    updateGeometry();
 }
 
 
@@ -3435,6 +3442,7 @@ void QAbstractItemViewPrivate::_q_rowsInserted(const QModelIndex &index, int sta
         QAccessible::updateAccessibility(&accessibleEvent);
     }
 #endif
+    updateGeometry();
 }
 
 /*!
@@ -3459,6 +3467,7 @@ void QAbstractItemViewPrivate::_q_columnsInserted(const QModelIndex &index, int
         QAccessible::updateAccessibility(&accessibleEvent);
     }
 #endif
+    updateGeometry();
 }
 
 /*!
@@ -4084,7 +4093,14 @@ void QAbstractItemViewPrivate::interruptDelayedItemsLayout() const
     delayedPendingLayout = false;
 }
 
-
+void QAbstractItemViewPrivate::updateGeometry()
+{
+    Q_Q(QAbstractItemView);
+    if (sizeAdjustPolicy == QAbstractScrollArea::AdjustIgnored)
+        return;
+    if (sizeAdjustPolicy == QAbstractScrollArea::AdjustToContents || !shownOnce)
+        q->updateGeometry();
+}
 
 QWidget *QAbstractItemViewPrivate::editor(const QModelIndex &index,
                                           const QStyleOptionViewItem &options)
diff --git a/src/widgets/itemviews/qabstractitemview_p.h b/src/widgets/itemviews/qabstractitemview_p.h
index 86eab174ed..5da22615e2 100644
--- a/src/widgets/itemviews/qabstractitemview_p.h
+++ b/src/widgets/itemviews/qabstractitemview_p.h
@@ -127,6 +127,8 @@ public:
     void doDelayedItemsLayout(int delay = 0);
     void interruptDelayedItemsLayout() const;
 
+    void updateGeometry();
+
     void startAutoScroll()
     {   // ### it would be nice to make this into a style hint one day
         int scrollInterval = (verticalScrollMode == QAbstractItemView::ScrollPerItem) ? 150 : 50;
diff --git a/src/widgets/itemviews/qheaderview.cpp b/src/widgets/itemviews/qheaderview.cpp
index edfbc5c8f1..0dbf0a6a76 100644
--- a/src/widgets/itemviews/qheaderview.cpp
+++ b/src/widgets/itemviews/qheaderview.cpp
@@ -550,6 +550,22 @@ QSize QHeaderView::sizeHint() const
 }
 
 /*!
+    \reimp
+*/
+
+void QHeaderView::setVisible(bool v)
+{
+    bool actualChange = (v != isVisible());
+    QAbstractItemView::setVisible(v);
+    if (actualChange) {
+        QAbstractScrollArea *parent = qobject_cast<QAbstractScrollArea*>(parentWidget());
+        if (parent)
+            parent->updateGeometry();
+    }
+}
+
+
+/*!
     Returns a suitable size hint for the section specified by \a logicalIndex.
 
     \sa sizeHint(), defaultSectionSize(), minimumSectionSize(),
@@ -918,6 +934,18 @@ void QHeaderView::resizeSection(int logical, int size)
         d->doDelayedResizeSections();
         r = d->viewport->rect();
     }
+
+    // If the parent is a QAbstractScrollArea with QAbstractScrollArea::AdjustToContents
+    // then we want to change the geometry on that widget. Not doing it at once can/will
+    // cause scrollbars flicker as they would be shown at first but then removed.
+    // In the same situation it will also allow shrinking the whole view when stretchLastSection is set
+    // (It is default on QTreeViews - and it wouldn't shrink since the last stretch was made before the
+    // viewport was resized)
+
+    QAbstractScrollArea *parent = qobject_cast<QAbstractScrollArea *>(parentWidget());
+    if (parent && parent->sizeAdjustPolicy() == QAbstractScrollArea::AdjustToContents)
+        parent->updateGeometry();
+
     d->viewport->update(r.normalized());
     emit sectionResized(logical, oldSize, size);
 }
diff --git a/src/widgets/itemviews/qheaderview.h b/src/widgets/itemviews/qheaderview.h
index 8fcd8d7a36..0b94eedf78 100644
--- a/src/widgets/itemviews/qheaderview.h
+++ b/src/widgets/itemviews/qheaderview.h
@@ -84,6 +84,7 @@ public:
     int offset() const;
     int length() const;
     QSize sizeHint() const;
+    void setVisible(bool v);
     int sectionSizeHint(int logicalIndex) const;
 
     int visualIndexAt(int position) const;
diff --git a/src/widgets/itemviews/qtableview.cpp b/src/widgets/itemviews/qtableview.cpp
index 573df1db6a..37c52948b0 100644
--- a/src/widgets/itemviews/qtableview.cpp
+++ b/src/widgets/itemviews/qtableview.cpp
@@ -1056,6 +1056,19 @@ QTableView::~QTableView()
 /*!
   \reimp
 */
+QSize QTableView::viewportSizeHint() const
+{
+    Q_D(const QTableView);
+    QSize result( (d->verticalHeader->isHidden() ? 0 : d->verticalHeader->width()) + d->horizontalHeader->length(),
+                  (d->horizontalHeader->isHidden() ? 0 : d->horizontalHeader->height()) + d->verticalHeader->length());
+    result += QSize(verticalScrollBar()->isVisible() ? verticalScrollBar()->width() : 0,
+                    horizontalScrollBar()->isVisible() ? horizontalScrollBar()->height() : 0);
+    return result;
+}
+
+/*!
+  \reimp
+*/
 void QTableView::setModel(QAbstractItemModel *model)
 {
     Q_D(QTableView);
diff --git a/src/widgets/itemviews/qtableview.h b/src/widgets/itemviews/qtableview.h
index 824348dbe8..db956480d6 100644
--- a/src/widgets/itemviews/qtableview.h
+++ b/src/widgets/itemviews/qtableview.h
@@ -118,6 +118,8 @@ public:
 
     void sortByColumn(int column, Qt::SortOrder order);
 
+    QSize viewportSizeHint() const;
+
 public Q_SLOTS:
     void selectRow(int row);
     void selectColumn(int column);
diff --git a/src/widgets/itemviews/qtreeview.cpp b/src/widgets/itemviews/qtreeview.cpp
index 70523815e8..962ed97762 100644
--- a/src/widgets/itemviews/qtreeview.cpp
+++ b/src/widgets/itemviews/qtreeview.cpp
@@ -335,6 +335,7 @@ void QTreeView::setHeader(QHeaderView *header)
             this, SLOT(updateGeometries()));
 
     setSortingEnabled(d->sortingEnabled);
+    d->updateGeometry();
 }
 
 /*!
@@ -2619,6 +2620,35 @@ void QTreeView::selectAll()
 }
 
 /*!
+  \reimp
+*/
+QSize QTreeView::viewportSizeHint() const
+{
+    Q_D(const QTreeView);
+    d->executePostedLayout(); // Make sure that viewItems are up to date.
+
+    if (d->viewItems.size() == 0)
+        return QAbstractItemView::viewportSizeHint();
+
+    // Get rect for last item
+    const QRect deepestRect = visualRect(d->viewItems.last().index);
+
+    if (!deepestRect.isValid())
+        return QAbstractItemView::viewportSizeHint();
+
+    QSize result = QSize(d->header->length(), deepestRect.bottom() + 1);
+
+    // add size for header
+    result += QSize(0, d->header->isVisible() ? d->header->height() : 0);
+
+    // add size for scrollbars
+    result += QSize(verticalScrollBar()->isVisible() ? verticalScrollBar()->width() : 0,
+                    horizontalScrollBar()->isVisible() ? horizontalScrollBar()->height() : 0);
+
+    return result;
+}
+
+/*!
   \since 4.2
   Expands all expandable items.
 
diff --git a/src/widgets/itemviews/qtreeview.h b/src/widgets/itemviews/qtreeview.h
index 73f11f1a48..fae814c6f6 100644
--- a/src/widgets/itemviews/qtreeview.h
+++ b/src/widgets/itemviews/qtreeview.h
@@ -144,6 +144,8 @@ public:
     void dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles = QVector<int>());
     void selectAll();
 
+    QSize viewportSizeHint() const;
+
 Q_SIGNALS:
     void expanded(const QModelIndex &index);
     void collapsed(const QModelIndex &index);